supplementary materials

In the title compound, [Ir(C10H15)(C11H8N)(N3)], the IrIII ion is coordinated by three anionic ligands, namely, pentamethylcyclopentadienyl (Cp*-), 2-(pyridin-2-yl)phenyl (ppy-) and azide (N3-), and adopts a three-legged piano-stool geometry The coordination mode of N3- is typical for Cp*IrIII-N3 complexes, with an Ir-N(N3) bond length of 2.125 (2) Å and an Ir-N=N bond angle of 116.5 (2)°. The N3- ligand is almost linear [N=N=N = 176.0 (3)°], and the N=N bond length between the central and coordinating N atom and that between the central and non-coordinating terminal N atom are 1.194 (3) and 1.157 (3) Å, respectively. For the ppy- ligand, the Ir-C and Ir-N bond lengths are 2.066 (3) and 2.079 (3) Å, respectively, which are rather close to each other, compared to the related IrIII- or RhIII-ppy complexes. The Ir-C(Cp*) bond lengths vary in the range 2.163 (2)-2.232 (2) Å, indicating a strong trans influence of the cyclometallated C-donor atom of the ppy- ligand.

In previous studies we have prepared a number of iridium(III) azido complexes,
[Cp*IrIII(N3)(L–L')] (Cp* = pentamethylcyclopentadienyl,
L–L' = various kinds of bidentate chelate ligands), and investigated
their structures and photochemical reactivities. Among them, complexes of
[Cp*Ir(N3)(Me2dtc)] (Me2dtc- =
N,N-dimethyldithiocarbamate) and [Cp*Ir(N3)(2-Spy)] (2-Spy-
= 2-pyridinethiolate) afforded interesting photolysis products with two-legged
piano-stool structures, [Cp*Ir{SC(NMe2)SN}] and [Cp*Ir(1-N-2Spy)],
respectively, by insertion of a N-atom originating from the coordinated azido
ligand, into the Ir–S and Ir–N(py) bonds, respectively
(Sekioka et al., 2005). In contrast,
photolysis of the related complexes with an N—N, N—P or P—P type
four-membered chelate ligand (i.e., 1,8-naphthyridine,
2-diphenylphosphinopyridine or bis(dimethylphosphino)methane) gave a
complicated mixture of uncharacterized products, due probably to reductive
elimination of the coordinated azide (Suzuki et al., 2009). In
the case
of [Cp*Ir(N3)(bpy)]PF6 (bpy = 2,2'-bipyridine), photolysis in acetonitrile
produced a 5-methyltetrazolato complex, [Cp*Ir(N3)(MeCN4)]+, which was
confirmed by 1H NMR spectroscopy (Kotera et al., 2008). In
addition,
the X-ray structural analysis of the bpy complex,
[Cp*IrIII(N3)(bpy)]PF6, revealed some structural characteristics
different from those of the other [Cp*Ir(N3)(L–L')] complexes
(Suzuki, 2005; Suzuki et al., 2009).
For instance, the Ir—N(N3) bond
in the bpy complex [2.230 (6) Å] was longer by ca 0.1 Å than the
typical Ir—N(N3) bond lengths in the other [Cp*Ir(N3)(L–L')]
complexes.
Triatomic unit of N3- was almost linear as usual, but the N—N
bond length between the central and coordinated N atoms was unusually longer
by ca 0.25 Å than that between the central and non-coordinated
terminal N atoms. In this study, we have prepared and characterized the
analogous Cp*IrIII(N3) complex with a structurally similar but an anionic
2-(pyridin-2-yl)phenyl (ppy-) ligand, [Cp*Ir(N3)(ppy)].

The title compound crystallized in a monoclinic space group
P21/n with Z = 4. The IrIII ion was coordinated by
three anionic ligands, Cp*-, ppy- and N3-, and it took a three-legged
piano-stool structure. The ppy- ligand formed a planar chelate,
having the Ir1—C11 bond of 2.066 (2) Å and the Ir1—N22 bond of 2.079 (2) Å.
It is noted that the difference between the Ir—C and Ir—N bond lengths
is not so large (0.013 Å), compared to the typical IrIII or RhIII
(MIII)–ppy complexes, where the M—C bond is significantly shorter
than the M—N bond (Takayama et al., 2013). In some cases of
IrIII–ppy complexes with a simple halide, similarly small differences in
the Ir—C and Ir—N bonds were also reported; for example, 0.016 Å in
[Cp*IrCl(ppy)] (Boutadla et al., 2009) and 0.029 Å in
[Cp*IrI(ppy)]
(Park-Gehrke et al., 2009). These small differences may be due
to a
partial configurational disorder of the ppy coordination.

The five Ir1—Cn(Cp*) bond lengths are
2.175 (2), 2.163 (2), 2.201 (2), 2.230 (2)
and 2.232 (2) Å for n = 1–5, respectively (Table 1).
Two relatively long (to C4 and
C5) bonds are approximately trans to the C-donor atom of ppy- ligand.
A similar elongation of the Ir—C bonds are also observed in the other
mononuclear [Cp*IrIII(ppy)X] complexes (Park-Gehrke et al.,
2009; Takayama et al., 2013), indicating a strong
trans
influence of the cyclometalated C-donor. The Ir1—C3 bond, which is
trans to the N-donor of ppy-, is a little longer than the other two;
this may indicate a partial configurational disorder of the N– and C-donor of
ppy- ligand in the Cp*IrIII(ppy) complexes.

In the crystal structure there are no solvent molecules of crystallization.
Further, any characteristic intermolecular interaction is not observed in this
crystal.

When UV light was irradiated to an acetonitrile solution of this complex, a
tetrazolato complex, [Cp*Ir(ppy)(MeCN4)] (Takayama et al.,
2013) was
formed, which was confirmed by 1H NMR spectroscopy.

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes)
are estimated using the full covariance matrix. The cell e.s.d.'s are taken
into account individually in the estimation of e.s.d.'s in distances, angles
and torsion angles; correlations between e.s.d.'s in cell parameters are only
used when they are defined by crystal symmetry. An approximate (isotropic)
treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s.
planes.